Dementia Rating Scale psychometric study and its
applicability in long term care institutions in Brazil
Estudo psicométrico da Escala de Avaliação de Demência e sua aplicabilidade em
instituições de longa permanência no Brasil
Alessandro Ferrari Jacinto1, Ana Cristina Procópio de Oliveira Aguiar1, Fabio Gazelato de Melo Franco1,
Miriam Ikeda Ribeiro1, Vanessa de Albuquerque Citero2
Study carried out at Hospital Israelita Albert Einstein – HIAE, São Paulo (SP), Brazil.
1 Hospital Israelita Albert Einstein – HIAE, São Paulo (SP), Brazil.
2 Hospital Israelita Albert Einstein – HIAE, São Paulo (SP), Brazil; Universidade Federal de São Paulo – UNIFESP, São Paulo (SP), Brazil.
Corresponding author: Alessandro Ferrari Jacinto – Avenida Albert Einstein, 627 – Morumbi – Zip code: 05651-901 – São Paulo (SP), Brazil – Phone: (55 11) 2151-0904 – E-mail: alessandrofj@einstein.br
Received on: Jan 18, 2012 – Accepted on: Aug 25, 2012
Conflict of interest: none.
ABSTRACT
Objective: To evaluate the diagnostic sensitivity, specificity, and agreement of the Dementia Rating Scale with clinical diagnosis of cognitive impairment and to compare its psychometric measures with those from Mini Mental State Examination. Methods: Eighty-six elders from a long-term care institution were invited to participate in a study, and fifty-eight agreed to participate. The global health assessment protocol applied to these elders contained Mini Mental State Examination and Dementia Rating Scale. Clinical diagnose of cognitive impairment was performed by experts using the DSM-IV criteria. Dementia Rating Scale score was correlated to the Mini Mental State Examination. Sensitivity and specificity of the Dementia Rating Scale and the Mini Mental State Examination were calculated.
Results: Twenty-two (37.9%) elders had cognitive impairment (8.6% presented with mental cognitive impairment and 29.3% dementia). The Mini Mental State Examination and the Dementia Rating Scale classified 31% and 55.2% as presenting with cognitively impaired. Dementia Rating Scale and the Mini Mental State Examination scores presented a strong correlation. Dementia Rating Scale had a higher sensitivity than Mini Mental State Examination (86.4% versus 61.9%). Dementia Rating Scale presented lower diagnostic specificity than Mini Mental State Examination (63.9% versus 86.5%). Considering Dementia Rating Scale and Mini Mental State Examination, the diagnostic agreement between them and the clinical diagnosis was similar. Conclusions: Dementia Rating Scale showed a high sensitivity to detect cognitive impairment in this population, and it could be a useful tool in these settings.
Keywords: Cognition; Delirium, dementia, amnestic, cognitive disorders; Neuropsychological tests; Homes for the aged; Aged; Sensitivity and specificity; Scales
RESUMO
Objetivo: Avaliar a sensibilidade e a especificidade diagnósticas, e a concordância da Escala de Avaliação de Demência, com diagnóstico clínico de comprometimento cognitivo, e compará-las com as do Miniexame do Estado Mental. Métodos: Oitenta e seis idosos de uma instituição de longa permanência foram convidados a participar do estudo e, destes, 58 concordaram em fazê-lo. A avaliação continha Miniexame do Estado Mental e Escala de Avaliação de Demência. O diagnóstico clínico de comprometimento cognitivo foi realizado por especialistas que utilizaram os critérios do DSM-IV. Escores da Escala de Avaliação de Demência e do Miniexame do Estado Mental foram correlacionados e suas sensibilidade e especificidade, obtidas.
Resultados: Vinte e dois (37,9%) idosos tinham comprometimento cognitivo (8,6% apresentaram comprometimento cognitivo leve e 29,3% demência). O Miniexame do Estado Mental e a Escala de Avaliação de Demência classificaram 31% e 55,2% como apresentando comprometimento cognitivo. Os escores da Escala de Avaliação de Demência e do Miniexame do Estado Mental tiveram uma forte correlação. A Escala de Avaliação de Demência teve uma sensibilidade maior do que o Miniexame do Estado Mental (86,4% versus 61,9%) e a especificidade foi menor (63,9% versus 86,5%). A concordância diagnóstica da Escala de Avaliação de Demência e do Miniexame do Estado Mental com a o diagnóstico clínico foi similar. Conclusão: A Escala de Avaliação de Demência mostrou uma sensibilidade maior na detecção de comprometimento cognitivo na população estudada e poderia ser um instrumento útil para aplicação em instituições de longa permanência.
INTRODUCTION
As population ages(1,2), long term care institutions
(LTCI) play a crucial role in the elderly care. Although LTCIs are historically characterized as places where care-demanding people live, more frequently healthy elderly have decided to live in these facilities for many different reasons (more intense social contact or even enjoying what is offered at LTCIs such as balanced and proper food, recreational and physical activity and specialized medical care). LTCI are often divided into areas based on residents’ dependency on daily living activities. In general, more dependent residents are those who required more expenses with their care plans(3).
Cognitive impairment (CI) is one of the main reasons for elders’ institutionalization and often contributes for increased dependency in LTCI. Once detected,
CI should be followed-up(4). Most of dementias are
not curable diseases, however, there are potentially
reversible cases(5). Regarding those considered incurable
dementias, multidisciplinary assessment and planning of the patient’s future are important issues that make
early CI worthwhile in LTCI(4).
Early detection of CI in elderly living in LTCI allows an efficient treatment to be offered; therefore independency can be maintained longer and less money
would be demanded(6).
There are brief instruments that can be used in the cognitive screening of different population sets including those living at LTCI. The Mini Mental State
Examination (MMSE)(7) has been widely studied
in different populations, including in Brazil. Its performance is closely related to schooling and cutoff scores for the Brazilian population have been
well-established(8,9). Although highly sensitive, its specificity
can be lower since it is influenced by other than dementia CI such as delirium and psychosis.
The Mattis Dementia Rating Scale (DRS) is an instrument that unable to assess easily the cognitive
status(10). It takes 30 to 40 minutes to be applied.
The 36 tasks are divided into 5 subscales, each one evaluating different cognitive areas: attention, initiation/ perseveration, construction, conceptualization and memory. DRS has some advantages over MMSE since it provides more detailed information about the cognitive functions that are impaired or preserved, because it allows appliers to get a more detailed evaluation of a
greater number of cognitive areas(11). Also, the DRS has
shown to be efficient in detecting mild CI and different stages of dementia. There are Brazilian studies in which schooling was taken into consideration and cutoff scores have been published(12).
OBJECTIVE
The aim of this study was to evaluate the diagnostic sensitivity, specificity, and agreement of the DRS with clinical diagnosis of CI (dementia or mild CI), and to compare these psychometric measures with the MMSE scores.
METHODS
This study was carried out at the Albert Einstein LTCI, a Brazilian facility for elderly that includes a nursing home service, an assisted living facility, and an outpatient geriatric clinic. Residents dependency status were classified by a team consensus using the Functional
Independence Measure (FIM)(13).
It was a cross-sectional study with 86 elders being invited to participate; they were independent and semi-dependent residents living in the LTCI. Fifty-eight of them agreed to participate in the study; the remaining 28 who refused had no statistical difference in relation to gender, age and dependency level (p>0.05) when compared to the included ones. The participants had 60 or more years and mean educational level of 10 years.
The global health assessment protocol applied to these elders contained tests for cognitive status evaluation including the MMSE and DRS. Clinical diagnosis was performed by experts using the
DSM-IV diagnostic criteria for dementia(14) to classify
the individuals as demented or non-demented, and the Petersen’s diagnostic algorithm for amnestic or
non amnestic mild CI(15). The three measurements
of CI were dichotomized into “presence” and “absence” of CI according to cutoff scores of Brazilian
previous studies(8,12). Clinical diagnosis was comprised
“absence” (no impairment) and “presence” (dementia or mild CI).
DRS score was correlated to MMSE score using the Spearman Coefficient Correlation test. Taking clinical criteria as the gold standard for CI diagnosis, the diagnostic agreement between clinical criteria and DRS, and clinical criteria and MMSE were examined using kappa measurement. Sensitivity and specificity of the DRS and the MMSE were calculated.
RESULTS
Thirty-six subjects (62.1%) had no CI regarding the clinical diagnosis criteria and 22 (37.9%) had CI (8.6% CI and 29.3% dementia). According to MMSE, 31% were classified as cognitively impaired whilst for DRS, 55.2% (Table 1).
DRS and MMSE scores presented a strong correlation (r=0.59; p<0,001). DRS had a higher sensitivity than MMSE to identify CI (86.4% versus 61.9%). To identify the absence of cognitive deficits, DRS presented lower diagnostic specificity than MMSE (63.9% versus 86.5%). Considering DRS and MMSE, the diagnostic agreement between both and clinical diagnosis was similar (Table 2).
The table 3 shows descriptively the results of table 2. Once “no impairment” was diagnosed, MMSE correctly detected the absence of CI in 86.1% (52.8% ±33.3%) whilst DRS in 63.9% (52.8%±11.1%). For mild CI, MMSE detected correctly the presence of CI in 40% whilst DRS in 60% (40±%20%). For dementia, MMSE detected correctly the presence of CI in 64.7% whilst DRS in 94.1% (64.7%±29.4%).
Table 1. Distribution of “presence” or “absence” of cognitive impairment
Cognitive impairment by Absence
n (%)
Presence n (%)
Mini Mental State Examination 40 (69.0) 18 (31.0)
Dementia Rating Scale 26 (44.8) 32 (55.2)
Clinical diagnosis 36 (62.1) 22 (37.9)
Table 2. Diagnosis agreement, sensitivity and specificity of the Mini Mental Status Examination and Dementia Rating Scale
Cognitive impairment by
Clinical diagnosis of cognitive impairment
Kappa p-value
Absence n (%)
Presence n (%)
Mini Mental State Examination Absence 32 (86.5)* 8 (38.1) 0.499 <0.001
Presence 5 (13.5) 13 (61.9)**
Dementia Rating Scale Absence 23 (63.9)* 3 (13.6) 0.462 <0.001
Presence 13 (36.1) 19 (86.4)**
*Specificity; **sensitivity.
Table 3. Distribution of possible combinations among clinical diagnostic (gold standard) and Mini Mental State Examination and Dementia Rating Scale classification
Clinical diagnosis Mini Mental State Examination Dementia Rating Scale
Subjects considering clinical diagnosis
n (%)
No impairment No impairment No impairment 19 (52.8)
Impairment present No impairment 4 (11.1)
No impairment Impairment present 12 (33.3)
Impairment present Impairment present 1 (2.8)
Mild cognitive defficiency Impairment present No impairment 0 (0)
No impairment Impairment present 1 (20.0)
No impairment No impairment 2 (40.0)
Dementia Impairment present Impairment present 11 (64.7)
Impairment present No impairment 0 (0)
No impairment Impairment present 5 (29.4)
No impairment No impairment 1 (5.9)
DISCUSSION
The medical literature on LTCI issues, including discussions about useful instruments to assess CI in the institutionalized elderly, is scarce. Our study showed
since this condition is more prevalent in these facilities
than in the community(16). The prevalence of CI in
previous Brazilian community studies ranged from 4.3%
to 29.7%(17-19). As expected in a LTCI, the prevalence of
this study was higher. Considering specific diagnosis, CI prevalence found in the present study was higher than that found in a Brazilian community report on this
issue (1.6%)(20). Dementia prevalence was much higher
than in other Brazilian studies (range from 7.1% to
7.2%), being this finding already expected(21-23).
It is known that MCI diagnosis is the basis for early detection of CI, although there is no consensus about this diagnostic process improvement. According to previous
studies(24), the MMSE is not adequate to recognize CI,
being necessary to use a neuropsychological battery in order to complete the evaluation. The DRS itself is not a neuropsychological battery though it is able to give more details on cognitive status than MMSE. Besides, it can be applied by any trained health professional, but not exclusively to psychologists(25). Along with clinical criteria
it would be a useful instrument in LTCIs(26). In these
settings, DRS can be incorporated to the geriatric global assessment facilitating residents follow-up.
There are some limitations to be considered. This study was developed at only one LTCI with no randomized sample. To increase the accuracy of CI diagnosis it would be appropriate to have a larger sample, with an estimation of at least 20 CI patients to facilitate the statistical approach.
However, this study brings a contribution showing CI data in a Brazilian LTCI and a clinical implication to be considered, that is routine use of DRS in LTCI assessments, that allows early detection of CI in elderly people and consequently enables an efficient treatment to be offered.
CONCLUSION
DRS is a useful instrument for cognitive assessment in LTCIs. In this study, it was more sensitive than MMSE.
ACKNOWLEDGMENTS
We would like to thank all the staff at Hospital Israelita Albert Einstein (Unidade Vila Mariana) that contributed to this study.
REFERENCES
1. Karachi A, Veras RP, Ramos LP. [The aging of the world population. A new challenge]. Rev Saúde Pública. 1987;21(3):200-10. Article in Portuguese. 2. Instituto Brasileiro de Geografia e Estatística (IBGE). Censo demográfico. IBGE:
Rio de Janeiro; 2010.
3. Camarano AA, Kanso S. As instituições de longa permanência para idosos no Brasil. Rev Bras Estud Popul. 2010;27(1):232-5.
4. Jacinto AF, Brucki S, Porto CS, Martins MA, Nitrini R. Detection of cognitive impairment in the elderly by general internists in Brazil. Clinics. 2011;66(8): 1379-84.
5. Takada LT, Nitrini R, Caramelli P, Radanovic M, Anghinah R, Hartmann APBJ, et al. Prevalence of potentially reversible dementias in a dementia outpatient clinic of tertiary university-affiliated hospital in Brazil. Arq Neuropsiquiatr. 2003;61(4):925-9.
6. Kim EY, Yang BM. Cost-effectiveness of long-term care services in South Korea. Arch Gerontol Geriatr. 2005;40(1):73-83.
7. Folstein MF, Folstein SE, McHugh PR. “Mini-mental state”. A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res. 1975;12(3):189-98.
8. Brucki SMD, Nitrini R, Caramelli P, Bertolucci PH, Okamoto IH. [Suggestions for utilization of the mini-mental state examination in Brazil]. Arq Neuropsiquiatr. 2003;61(3B):777-81. Article in Portuguese.
9. Bertolucci PHF, Brucki S, Campacci SR, Juliano Y. [The Mini-Mental State Examination in an outpatient population: influence of literacy]. Arq Neuropsiquiatr. 1994;52(1):1-7. Article in Portuguese.
10. Mattis S. Dementia Rating Scale. Professional Manual. Florida: Psychological Assessment Resources; 1998.
11. Aguiar ACPO, Ribeiro MI, Jacinto AF. Subjective memory complaints in the elderly may be related to factors other than cognitive deficit. Dement Neuropsychol. 2010;4(1):54-7.
12. Porto CS, Fichman HC, Caramelli P, Bahia VS, Nitrini R. Brazilian version of the Mattis dementia rating scale: diagnosis of mild dementia in Alzheimer’s disease. Arq Neuropsiquiatr. 2003;61(2B):339-45.
13. Riberto MM, Jucá SSH, Sakamoto H, Pinto PPN, Battistella LR. Validation of the Brazilian version of the Functional Independence Measure. Acta Fisiatr. 2004;11(2):72-6.
14. American Psychiatry Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington (DC): American Psychiatric Press; 1994. 15. Petersen RC. Clinical practice. Mild cognitive impairment. N Engl J Med.
2011;364(23):2227-34.
16. Feldman H, Clarfield AM, Brodsky J, King Y, Dwolatzky T. An estimate of the prevalence of dementia among residents of long-term care geriatric institutions in the Jerusalem area. Int Psychogeriatr. 2006;18(4):643-52. 17. Almeida Filho N, Santana VS, Pinho AR. Estudo epidemiológico dos transtornos
mentais em uma população de idosos: área urbana de Salvador. J Bras Psiq. 1984;33(2):114-20.
18. Blay SL, Mari JJ, Ramos LR. The use of the face-hand test to screen for organic brain syndromes. A pilot study. Rev Saude Publ. 1989;23(5): 395-400. Article in English, Portuguese.
19. Veras RP, Coutinho E. [Prevalence of depression and organic cerebral syndrome in the elderly population, Brazil]. Rev Saude Pub. 1991;25(3):209-17. Article in Portuguese.
20. Bottino CM, Azevedo D Jr, Tatsch M, Hototian SR, Moscoso MA, Folquitto J, et al. Estimate of dementia prevalence in a community sample from São Paulo, Brazil. Dement Geriatr Cogn Disord. 2008;26(4):291-9.
21. Herrera E, Caramelli P, Silveira ASB, Nitrini R. Epidemiologic Survey of Dementia in a Community-Dwelling Brazilian Population. Alzheimer Dis Assoc Disord. 2002;16(2):103-8.
22. Lopes MA, Hototian SR, Bustamante SE, Azevedo D, Tatsch M, Bazzarella MC, et al. Prevalence of cognitive and functional impairment in a community sample in Ribeirão Preto, Brazil. Int J Geriatr Psychiatry. 2007;22(8): 770-6.
23. Laks J, Batista EM, Guilherme ER, Contino AL, Faria ME, Rodrigues CS, et al. Prevalence of cognitive and functional impairment in community-dwelling elderly: importance of evaluating activities of daily living. Arq Neuropsiquiatr. 2005;63(2A):207-12.
JC, et al. Neuropsychiatric symptoms in Alzheimer disease and cognitively impaired, nondemented elderly from a community-based sample in Brazil: prevalence and relationship with dementia severity. Am J geriatr Psychiatry. 2006;14(5):438-45.
25. Diniz BS, Nunes PV, Yassuda MS, Pereira FS, Flaks MK, Viola LF, et al.
Mild cognitive impairment: cognitive screening or neuropsychological assessment? Rev Bras Psiquiatr. 2008;30(4):316-21.
